The invention is based on a pump unit for a brake system of a vehicle.
In a known pump unit, an electric motor is fastened to a pump housing. The disclosure of European patent application EP 0 699 571 A1 indicates a pump unit in which an electric motor is flange mounted to the pump housing and screwed tight via two motor fastening screws. So that the pump unit can be suspended inside a vehicle, blind hole-like recesses are disposed on two different sides of the pump housing and bush-like rubber-elastic elements are slid into these recesses. The rubber-elastic elements hold suspension bolts. Finally, a third blind hole-like bore Is also provided on a third side of the pump housing and a rubber elastic element is likewise slid into this bore. In this way, the pump unit is suspended in an elastically resilient manner at three suspension points in the body of the vehicle and is positionally secured to a sufficient degree.
In the known embodiment, it is disadvantageous that a large number of additional component pieces is required for the suspension of the pump unit in the vehicle body. It is also disadvantageous that a part of these component pieces is only slid in and can thus fall out before the installation of the pump unit into the vehicle body. It is additionally disadvantageous that a part of these component pieces protrudes a long way laterally and has a contour that is not easy to manufacture. It is furthermore disadvantageous that when installing the pump unit in the vehicle body, the suspension bolts must be secured against rotation through the use of a special tool and a fastening means with an internal thread must be screwed onto the suspension bolts through the use of another tool. As a result, installing the pump unit in the vehicle body is costly and is almost impossible to execute without special devices.
The pump unit according to the invention, has the advantage over the prior art that the number of component pieces required is significantly reduced.
The components that contribute to the connection between the pump unit and the vehicle body can advantageously be produced in a simple manner.
Also, it is advantageously assured without additional securing measures that no parts can inadvertently fall out even before the installation of the pump unit in the vehicle body.
The pump unit can be plugged together with the vehicle body in a simple manner. Another simple fastening screw can be advantageously used to improve the connection between the pump unit and the vehicle body.
Advantageous improvements and updates of the pump unit disclosed in the main claim are possible by means of the measures taken herein.
If the mated connecting piece is provided in a resilient or elastic material, then an easy-to-produce vibrational uncoupling of the pump unit from the body of the vehicle is thus advantageously produced.
By providing a recess associated with the vehicle body, the shaped part can advantageously be connected to the vehicle body in a very simple manner.
An advantageous, particularly easy-to-produce connection is produced when the screw head has a cylindrical outer surface which engages in a cylindrical inner surface provided on the mated connecting piece.
The motor fastening screw has a rotational driving feature so that during the mounting of the electric motor on the pump housing, a tool or a torque wrench can tighten the motor fastening screw. If this rotational driving feature is provided internally and so that it can be accessed on the end face, then the connection between the pump unit and the vehicle body is advantageously not impaired by the rotational driving feature and despite the rotational driving feature, the mated connecting piece can be embodied as simple in shape.
The radially protruding shoulder provided on the screw head offers the advantage that the pump unit can be fixed in the axial direction in relation to the vehicle body in a simple manner.
If two motor fastening screws are provided, which can be embodied identically and can both contribute to the connection between the pump unit and the vehicle body, then this offers the advantage that the mechanical strain is distributed.
If a fastening screw is additionally provided, with which the pump unit can be fixed on the vehicle body, then with a simple measure, it is advantageously assured that the screw head of the motor fastening screw cannot unintentionally slip out of the mated connecting piece provided on the vehicle body.
A particularly advantageous and suitable embodiment is one in which the electric motor is fastened to the pump housing via two motor fastening screws and both motor fastening screws are provided for the connection between the vehicle body and the pump unit, and the pump unit on the other hand is additionally secured with a fastening screw that is screwed into the pump housing. As a result, with a minimum of expenditure, a particularly secure connection is produced between the pump unit and the vehicle body.
If the thread provided on the pump housing is an internal thread, then a simple fastening screw can be used which is for the most part commercially available.
If two threads or if need be, more than two threads are provided on the pump unit for the attachment of a fastening screw, then this offers the advantage that by choice, one of the threads can be used in order to mount the pump unit to the vehicle body.
The shaped part comprised of resilient material which is disposed between the vehicle body and the fastening screw attains the advantage of a vibrational uncoupling between the pump unit and the vehicle body.